There is 1 ten in the number 10. In the decimal system, each digit's place value is based on powers of 10, so the digit in the tens place represents the quantity of tens in the number. In this case, the digit 1 in the tens place indicates there is 1 group of ten in the number 10.
Well, honey, there's just one ten in the number 10. It's not rocket science, darling. Just one little ol' ten hanging out all by itself in that number.